Wake and Sleep EEG in Patients With Huntington Disease: An eLORETA Study and Review of the Literature

The aim of the study was to evaluate the EEG modifications in patients with Huntington disease (HD) compared with controls, by means of the exact LOw REsolution Tomography (eLORETA) software. We evaluated EEG changes during wake, non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. Moreover, we reviewed the literature concerning EEG modifications in HD. Twenty-three consecutive adult patients affected by HD were enrolled, 14 women and 9 men, mean age was 57.0 +/- 12.4 years. Control subjects were healthy volunteers (mean age 58.2 +/- 14.6 years). EEG and polygraphic recordings were performed during wake (before sleep) and during sleep. Sources of EEG activities were determined using the eLORETA software. In wake EEG, significant differences between patients and controls were detected in the delta frequency band (threshold T = +/- 4.606; P < .01) in the Brodmann areas (BAs) 3, 4, and 6 bilaterally. In NREM sleep, HD patients showed increased alpha power (T = +/- 4.516; P < .01) in BAs 4 and 6 bilaterally; decreased theta power (T = +/- 4.516; P < .01) in the BAs 23, 29, and 30; and decreased beta power (T = +/- 4.516; P < .01) in the left BA 30. During REM, HD patients presented decreased theta and alpha power (threshold T = +/- 4.640; P < .01) in the BAs 23, 29, 30, and 31 bilaterally. In conclusion, EEG data suggest a motor cortex dysfunction during wake and sleep in HD patients, which correlates with the clinical and polysomnographic evidence of increased motor activity during wake and NREM, and nearly absent motor abnormalities in REM.